In today's Internet Protocol (IP) networks, network nodes, such as routers, switches, servers, and computers may be assigned IP addresses used to locate and identify the network nodes. In recent years, IP networks have been transitioning from an IP version 4 (IPv4) address and routing system to an IP version 6 (IPv6) address and routing system. One reason for the transition is because of IPv4 address exhaustion or the depletion of unallocated IPv4 addresses plaguing the infrastructure of IP networks. IPv4's addressing structure may provide about 232 (4,294,967,296) global addresses, which is no longer enough for the growing number of end users, hosts, and mobile devices. Deploying and ramping up IPv6 address and routing systems may resolve IPv4 address exhaustion because IPv6 may support about 3.4×1038 global addresses. Unfortunately, majority of the providers for Internet services and other Internet vendors are in the initial phases of transitioning over to IPv6 address and routing systems.
As IPv4 addresses become depleted, some Internet Service Providers (ISPs) may be unable to provide globally routable IPv4 addresses to all their clients. However, clients may need to access network nodes that have IPv4 addresses and no IPv6 addresses. To provide client access to the IPv4 networks, ISPs have employed different technologies, such as Dual-Stack Lite (DS-Lite) technology as described in the Internet Engineering Task Force (IETF) Request for Comments (RFC) 6333, published August 2011, which is incorporated herein as if reproduced by its entirety, to provide IPv4 services over IPv6 networks. More specifically, the DS-Lite technology may create an IPv4-in-IPv6 tunnel from a customer premises equipment (CPE) to an Address Family Transition Router (AFTR) within the ISP network. By employing DS-Lite, ISPs may avoid the need to allocate different IPv4 addresses to clients because different clients may use the same IPv4 addresses. Therefore, DS-Lite technology may be beneficial as IP networks continually transition from IPv4 address and routing systems to IPv6 address and routing systems.
In DS-Lite technology, DS-Lite tunnels (e.g. IPv4-in-IPv6 tunnels) may be stateless and may have no status information. As a result, failure detection and failover methods may not be available for DS-Lite tunnels. Without failure detection and failover methods, managing and diagnosing failures within the IP network may create problems for network operation and maintenance. For instance, the IP network may be unable to determine whether a DS-Lite tunnel is operational (e.g. in an “up” status or a “down” status). If a link problem or other failure occurs within the DS-Lite tunnel, the CPE may be unable to automatically switch over to another AFTR to continue network services. Instead, an operator may be needed to manually reroute the DS-Lite tunnel from the CPE to the another AFTR. Hence, a solution is needed to efficiently manage and detect failures within DS-Lite tunnels.